1. Field of the Invention
The present invention relates to integrated circuits and more particularly to lateral operation bipolar transistors.
2. Description of Related Art
Bipolar transistors are used to obtain higher output currents than MOS transistors. At present bipolar transistors have a vertical structure, generally including a buried extrinsic collector layer on top of which is an intrinsic collector region formed in the semiconductor bulk (substrate). On top of the intrinsic collector region is a base region covered with an emitter block.
Apart from the fact that these vertical structure, vertical operation bipolar transistors have a collector/bulk capacitance and a buried collector layer giving rise to isolation constraints, to increase the output current it is necessary to increase the width of the intrinsic base, i.e. to increase the overall surface area of the transistor. This gives rise to a problem in terms of integration density.
Accordingly, a need exists to provide a bipolar transistor and integrated circuit with a higher output current without increasing the overall surface area of the transistor so as to permit higher density integration.